Instead of only looking at directories, +eshell/goto now works with
files. If a directory is selected, set eshell to that directory. If
a file is selected, make eshell go to the directory where that file is
contained then use find-file.
Now I have separate modules for the additional new functions I
introduced for eshell and for the prompt function I made. Cleans up
the configuration a bit and makes it easier to examine those files on
their own, which I expect to grow.
